First: Affinit Designer is really great - thanks to the Affinity team! (Former-time Corel user, then Inkscape, now switched to Affinity due to CMYK and better color management)
My request:
I often use Save-As to generate numbered versions of files (as backups, and so that when I discuss them with a client, we can refer to which version we are talking about). In the Save As dialog, it appears that AD defaults to the folder where I last saved anything. This is very tricky when working on file
I think a good behavior would be:
1.) Save As: Default to the current file's folder.
2.) Export (pdf etc, but also for palettes): Default to the folder where I last exported to, when the current document was open. At first time, use current folder as in 1.
(Also Corel has always been much smarter with that, for decades. To be fair, its a different price range. If the Mac Version of the Corel Suite would have came out 3 years earlier, I would now happily be using Corel.)
Affin